The present invention relates to specific embodiments of a composite pressure sensitive adhesive construction which is releasable until a permanent seal is desirable. More specifically, the present invention relates to said composite pressure sensitive adhesive constructions which are very readily applied to any container, package, seam, or other item wherein an initial resealable connection is desired, followed by a later permanent-type bond.
Heretofore, various articles or methods have been utilized to join items together. One of the most common articles or methods has been the use of staples, paste, glue, and more recently, pressure sensitive tapes. However, often it is highly desirable to temporarily hold the items together. This renders the use of paste and glue impossible in that any separation after the paste and glue have been applied results in the destruction of a portion of the article. Similarly, the removal of staples will often tear a portion of the article.
Considering pressure sensitive adhesives, various techniques have been utilized and they generally are cumbersome, expensive, and result in a poor quality seal. For example, in the bonding or sealing together of two pieces of material such as the two cover edges of a pipe insulating jacket, paste or glue is highly undesirable in that the edges must first be cleaned, the paste applied, and the edges then held together for a period of time while the paste or glue dries. In addition to this, the installation is often in a very difficult work area, such as a ceiling, which requires an individual operating at the top of a high ladder.
One current method utilizing pressure sensitive adhesives involves a double face coated tape, that is, a tape system having a carrier, adhesive layers applied to both sides of the carrier, and release liners applied to the adhesive layers. One of the release liners would normally be removed so that the tape could be attached to one edge of the jacket or to the item. Upon installation, the remaining release liner would be removed and the adhesive contacted with the other edge. However, this method generally resulted in poor adhesion in that the remaining edge usually acquired dust, dirt, grease, and the like, either during warehousing, shipment, or installation.
Another system utilized heretofire is commonly called the "two-tape" method. According to this system, each tape contained a carrier having an adhesive layer on each side thereof. To each adhesive layer was added a release liner. One of the adhesive faces on each tape was added to each edge of the material either at the factory or on the job. If added on the job, the same problems set forth above were encountered in that the edges would be dirty, greasy, or the like, thus, a good bond of the tape generally was not obtained. Furthermore, an exact registration was difficult to obtain since the on-the-job application often involved working under difficult conditions. If one of the adhesive layers on each of the two tapes was applied to each edge during factory installation, a temporary bond of each edge to each other was not obtained, since, of course, the two remaining release layers would not adhere to each other. Thus, the item such as an insulated coolant or steam pipe jacket would freely open and was subject to abuse, damage, and the like, and further required the need to remove two liners.